Thomas a



5(No Model.) I

I T. A. EDISON.

ELECTRICAL RAILROAD.

Patented Mar. 1883.

UNITED STATES PATENT OFFICE.-

THQMAS A. EDISON, 0F MENLO PARK, NEW JERSEY.

ELECTRICAL RAILROAD.

SPECIFICATION forming part of Letters Patent No. 273,494, dated March 6,1883.

Application filed August 14, 1885.. (No model.)

To all whom it may concern Be it known that I, THOMAS A. EDISON, ofMenlo Park, in the county of Middl'esex and State of New Jersey, haveinvented a new and useful Improvement in Electrical Railroads, (Case No.467 and I do hereby declare that the following is a full and exactdescription of the same, referencebeing had to the accompanyin gdrawings, and to the letters of reference marked thereon.

Heretoforein electrical railroads wherein the two lines of traffic-railshave been used as part or all of the conductors for carrying the currentto and from the motor, or wherein a third or central line of rails hasbeen used for onehalf of the circuit, it has been attempted to lessenthe resistance and secure good conductivity by perfecting as far aspossible the joints between the ends of the rails; but this has beenonly partially successful, from the fact that loose joints have to beprovided at the ends of the rails to permit of expansion andcontraction, and the surfaces of the parts in contact becoming oxidizedthe contact becomes bad, making the combined resistance of the largenumber of joints in any section of the railroad considerable.

The object of the present invention is to reduce the resistance of thecircuit to the minimum. Thisisaccomplishedby providingeach line of railsused as a conductor with two or more continuous conducting-wires on oneor on each side of the line ofrails,which continuous wires pass beneaththe fish-plates at the joints of the rails, and are clamped by suchfish-plates against the rails. These wires may be bare copper wires,orthey can be insulated between the fish-plates and left bare where theypass under such fish-plates. The insulalation is scraped from the web ofthe rails at the ends, and the surfaces so scraped are cleaned, and maybe electroplated with nickel or silver or other metal not easilyoxidized by exposure to air and moisture, in order to make good contactwith the continuous wires. One of the conductors from the electricalgenerators is connected with the continuous wires of the line of railsand with the rails directly or with the wires only. It will be, seenthat the resistance of the lines of rails provided with the continuousconducting-wires will be greatly reduced thereby, since the wires willform a continuous metallic circuit to and from the rails over which themotor is passing, no matter where the motormay be on the track, more orless of the current being conducted through the lines of rails accordingto the resistance at the joints.

In the drawings, Figure l is a perspective view of a portion of twolines of rails having the continuous conducting-wires; and Fig. 2, across-section of a rail near the end of the same, showing thefish-plates in elevation.

A and B represent two lines ofT-rails. The rails of each line areconnected together by fishplates 41 b and bolts a, passing through thefishplates and rails, as usual. The rails are used as conductors of thecurrent, and are insulated as described in my application N o. 466.

E represents continuous conducting-wires, which are placed on one or oneach side of the rails of each line, and are clamped by the fishplatesagainst the ends of the rails. The continuous wire may be bare copperwire, or it can be insulated, except where it passes beneath thefish-plates. The webs of the rails at their ends have the insulationremoved therefrom, and are cleaned and preferably electroplated withnickel, silver, or other metal not easily oxidized by exposure to airand moisture, in order to make as good contact as possible with thecontinuous wires. The condoctors from the electrical generators areconnected with the wires and also with the rails or with the wiresalone. The current is conducted to and from the motor through wheelsresting on the rails, and a continuous metallic circuit will be formedto and from the rails over which the motor is passing by theconducting-wires, while part of the current will pass through the railsthemselves.v

What I claim is 1. In an electrical railroad,'a line of connected railshaving its conductivity increased by means of one or more continuousconductors attached thereto, substantially as setforth. 2. In anelectrical railroad,the combination, with a line of connected rails, ofone or more continuous conductors attached to such rails with which theymake electrical contact, suband making contact therewith at the jointsof stantially as set forth. to the rails, substantially as set forth.This specification signed and witnessed this 3. In an electricalrailr0ad,the combination, 7th day of July, 1882.

with a. line of connected rails, of one or more THOMAS A. EDISON.continuous conductors extending on one or on each side of the rails andclamped by means of the fish-plates against the ends of the railsWitnesses:

RICHD. N. DYER, EDWARD H. PYATT.

